This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

More detailed information about left posterior fascicular block

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

  • the normal left ventricular activation proceeds first down the left bundle branch, and then simultaneously through its two fascicles (left anterior fascicle and left posterior fascicle)
  • left posterior fascicular block (LPFB), also known as left posterior hemiblock, is much less common than left anterior fascicular block (LAFB) - this is due to a number of factors:
    • the posterior fascicle is a thicker structure than the anterior fascicle
    • posterior fascile has a dual blood supply
    • the anatomic location of the posterior fascicle is away from more turbulent ventricular blood flow
  • ECG changes in LPFB:
    • QRS interval <0.12 seconds
    • right axis deviation
    • rS pattern in the lateral limb leads (I and aVl)
    • qR complex in the inferior leads (II, III, and aVf)
    • no evidence of right ventricular hypertrophy
  • LPFB is a rare finding
    • LPFB is nonspecific for cardiac disease - however coronary artery disease is the most common cause
    • other associations for LPFB include hypertensive heart disease, aortic valvular pathology, and fibrocalcific disease of the cardiac skeleton
    • LPFB is the least common intraventricular conduction block seen in acute myocardial infarction
  • data on established LPFB are insufficient assess prognostic significance

Reference:

  1. Harrigan RA et al. Electrocardiographic manifestations: bundle branch blocks and fascicular blocks. The Journal of Emergency Medicine 2003;25(1):67–77
  2. Rowlands DJ.Left and right bundle branch block, left anterior and left posterior hemiblock. Eur Heart J. 1984 Mar;5 Suppl A:99-105.

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.